Curing fluorocarbon elastomers

Abstract

Fluorocarbon elastomer gum is compounded with curing agent comprising a polyhydroxy compound and a salt thereof with a salt-forming heterocyclic amine, the resulting compound gum is shaped and heated to form a cured shaped article such as automotive fuel line hose or O ring.

What is claimed is: 
     
       1. An elastomeric composition comprising a fluorocarbon elastomer gum, polyhydroxy compound, and at least 0.3 mmhr of a salt of an anion of a (A) polyhydroxy compound and a cation of a protonated   (B) heterocyclic amine having two nitrogen atoms at least one of which is a ring atom, wherein said heterocyclic amine is a dialkylaminopyridine or a diazabicyclo compound.   
     
     
       2. The composition of claim 1 wherein each of said polyhydroxy compounds is an aromatic bisphenol. 
     
     
       3. The composition of claim 1 wherein each of said polyhydroxy compounds is 2,2-bis(4-hydroxyphenyl) hexafluoropropane. 
     
     
       4. The composition of claim 1 wherein said heterocyclic amine (B) is a dialkylaminopyridine. 
     
     
       5. The composition of claim 1 wherein said heterocyclic amine (B) is 4-(N,N-dimethylamino)pyridine. 
     
     
       6. The composition of claim 1 wherein said heterocyclic amine (B) is an amine of the formula: ##STR8## where each subscript n is independently an integer of 2 to 8. 
     
     
       7. The composition of claim 1 wherein said heterocyclic amine (B) is 4,4-diazabicyclo[2.2.21octane. 
     
     
       8. The composition of claim 1 wherein said heterocyclic amine (B) is an amine of the formula: ##STR9## where each subscript n is independently an integer of 2 to 8. 
     
     
       9. The composition of claim 1 wherein said heterocyclic amine (B) is 1,8-diazabicyclo[5.4.0]-7-undecene. 
     
     
       10. The composition of claim 1 wherein said heterocyclic amine (B) is 1,5-diazabicyclo[d.3.0]-B-nonene. 
     
     
       11. The composition of claim 1 wherein both polyhydroxy compounds are 2,2-bis(4-hydroxyphenyl)-hexafluoroproane. and said heterocyclic amine (B) is 1,8-diazabicyclo[5.4.0]-7-undecene. 
     
     
       12. The composition of claim 1 further comprising an organo-onium compound. 
     
     
       13. The composition of claim 1 further comprising a quaternary phosphonium compound. 
     
     
       14. The composition of claim 1 further comprising triphenylbenzylphosphonium chloride. 
     
     
       15. The composition of claim 1 further comprising a fluoroaliphatic sulfonamide. 
     
     
       16. The composition of claim 1 further comprising C 8  F 17  SO 2  N(H)CH 3 . 
     
     
       17. The composition of claim 1 further comprising an acid acceptor. 
     
     
       18. The composition of claim 1 further comprising magnesium oxide and calcium hydroxide. 
     
     
       19. The composition of claim 1 wherein said gum is a polymer whose interpolymerized units are derived from vinylidene fluoride and one or more copolymerizable co-monomers. 
     
     
       20. An elastomeric composition which is curable in association with an inorganic acid acceptor, said composition comprising a fluorocarbon elastomer gum, free polyhydroxy compound, and at least 0.3 mmhr of an ex-situ salt of an anion or a polyhydroxy compound and a cation of a protonated heterocyclic amine having two nitrogen atoms at least one of which is a ring atom, wherein said heterocyclic amine is a dialkylaminopyridine or a diazabicyclo compound. 
     
     
       21. The composition of claim 20 wherein said free polyhydroxy compound, salt, and said organo-onium compound are present in said composition in amounts sufficient to crosslink said gum in an accelerated manner when heated in the presence of an inorganic acid acceptor. 
     
     
       22. A shaped article comprising the elastomeric composition of claim 1 in its curved state. 
     
     
       23. A method of compounding an elastomeric composition, comprising mixing fluorocarbon elastomer gum, polyhydroxy compound, and at least 0.3 mmhr of a salt of an anion of a polyhydroxy compound and a cation of a protonated heterocyclic amine having two nitrogen atoms at least one of which is a ring atom, wherein said heterocyclic amine is a dialkylaminopyridine or a diazabicyclo compound.